1. Field of the Invention
The invention relates generally to electrical switching apparatus and, more particularly, to sub-assemblies for electrical switching apparatus, such as circuit breakers. The invention also relates to auxiliary switch trays for circuit breaker sub-assemblies.
2. Background Information
Electrical switching apparatus, such as circuit breakers, as well as transfer switches, network protectors and the like, are often equipped with accessories such as, for example and without limitation, auxiliary switches, shunt trip devices, under voltage release devices, and bell alarms. Such devices can be employed in a variety of ways to provide signals indicating certain conditions within the apparatus and/or to initiate a change in status of the apparatus such as, for example, to trip open the separable contacts of the apparatus in response to an electrical fault condition (e.g., without limitation, current overload; short circuit; abnormal voltage).
In view of the increasing market trend to reduce the overall size of the circuit breaker, the space which is available within the circuit breaker housing is limited. In addition to size constraints, the location available for mounting accessories within the circuit breaker can also be problematic. For example, some locations for mounting the accessories in the circuit breaker have limited access for installing the accessories and, in some instances, blind installation is required, wherein it is not possible to mount the accessory within the circuit breaker housing. As a result, incorrect installation and/or damage to the accessories can result, and safety features of the circuit breaker can be adversely affected.
Traditionally, in order for various accessories to fit within the circuit breaker, they sometimes had to be custom made or modified. For example, auxiliary switches often consist of the combination of a micro-switch and a customized bracket, mount or shell which is required in order to adapt the micro-switch for proper installation in the circuit breaker. It is desirable to be able to use a variety of circuit breaker accessories such as, for example, micro-switches, in their stock or unaltered form, without requiring the micro-switch to be modified or a customized bracket, mount, or shell to be made. It is also desirable to be able to quickly and accurately removably install a plurality of auxiliary switches within the circuit breaker.
There is, therefore, room for improvement in electrical switching apparatus, such as circuit breakers, and in sub-assemblies therefor.